A conventional portable strapping apparatus has the shortcoming that it can not give strapping bands a sufficient tension and the strapping band is easily worn due to friction when it wraps strapping bands around an object. This is due to its imperfect tensioning mechanism design. On the other hand, average manually operated strapping apparatus can gradually stretch a strapping band until the band reaches a preset tension. However the operation of a manual strapping apparatus is slow in speed and poor in efficiency. Such apparatuses are not suitable for use with an automatic welding machine. Thus they can not meet the practical requirement in the industry.
In view of the above problem, the present invention is to provide a new type of portable strapping apparatus that comprises an innovative automatic tensioning and release mechanism that can be used in conjunction with automatic welding apparatuses and that can achieve a high efficiency that has never been seen in a conventional machine. Now the structure and features of the invention will be described in detail with reference to the accompanying drawings.